Snowblower sprocket breaking

[Northern Maine]

So I have a Kubota 72 in rear mount blower on my tractor, last winter the small sprocket broke, they replaced it but yesterday the replacement broke again just like the last one. This is the 3rd broken sprocket. They keep breaking near the set screw. Any thoughts on what could b causing this? There has only been around 10 inches of snow each time it's broken???? Frustrated to the point of just selling the blower...thanks

 

[mikester]

Post a picture of the part. Also post a pic of the assembly showing the chain.

Possible issues could be over tightened set screw, alignment, over tightened chain, overloaded part, poor quality issues with sprocket,...

Sprockets are cheap - its not like youve had to replace the gear box three times. Throwing the baby out with the bath water?

 

[Lil Foot]

Hard to diagnose over the internet, (pics would help) but it sounds like you need to find (or in my case make) a better quality, stronger sprocket.

 

[Yooper]

My guess is the shaft is bent.

 

[200mph]

So I have a Kubota 72 in rear mount blower on my tractor, last winter the small sprocket broke, they replaced it but yesterday the replacement broke again just like the last one. This is the 3rd broken sprocket. They keep breaking near the set screw. Any thoughts on what could b causing this? There has only been around 10 inches of snow each time it's broken???? Frustrated to the point of just selling the blower...thanks

Did you notify your dealer about the problem? Perhaps there is a known problem and they can provide a fix.

Perhaps the shear pins are not working as needed and transferring the loads to the next weak link.

Perhaps there is too much play in the key way.

 

[Dave_eng]

It would help if you provided the blower model info.

Pictures of the broken sprockets as well.

Dave

 

[Northern Maine]

Ok guys, it's a woods snowblower. The chain wasn't over tightened. It was properly lined up. The shear bolts are what woods recommends. The sprockets I keep ordering look like a white metal, very soft, all 3 sprockets have broken at the set screws. Almost like they are to thin in that area. Can anyone recommend a GD steel sprocket company, sprockets that are made from good steel?

 

[GreensvilleJay]

we really need the Wood's model number, hopefully can get 'parts diagrams' from them. Any 'small mechanical parts' place will/can get sprockets but without model info , I don't know pitch, # teeth, bore, etc. I've yet to have any spockets die in 50 years, let alone 3 in a row ..same use and I've abused some equipment over 5 decades !
It does sound as if a shaft is moving laterally,then under a 'load', sprocket fractures? NOT a normal shock load, say chewing a skid, as the shear blts never fail. Can't really help more without pictures and ID info. Buying a better sprocket won't help if the CAUSE of the failure isn't 'bad batch of sprockets'.

I would contact Wood's,they made it, they'll KNOW what and why...
Jay

 

[bucktail]

If it isn't too small, you can get a weldable sprockets. You buy the flange that fits your shaft, find the sprocket with the right size and number of teeth and weld them together. TSC, Fleet Farm, Runnings type stores should have them.

 

[shootem604]

Take it up with Woods, they should warranty their parts.

 

[GaryL]

I will also add that I had chains snapping all of a sudden on my blower. I looked at the bushings and bearings, and what was happening was that under load, it pulled the auger forward, which then misaligned the sprocket, snapping the chain. Possibly look at the same thing on your blower and see if your sprocket is what snaps instead of the chain.